(TOPEKA) - Authorities in northern Indiana say three Amish school teachers escaped a small schoolhouse that had filled with carbon monoxide gas.

Topeka Fire Chief Stewart Bender says the three teachers lived in the school in a rural area of LaGrange County. Bender tells The News Sun one of the teachers woke up about 5:30 a.m. Tuesday and alerted the others, one of who was initially unresponsive.

Bender says the three showed signs of carbon monoxide poisoning and were vomiting. One teacher was taken to a nearby hospital for treatment while medics treated the others at the scene about 40 miles northwest of Fort Wayne.

He says the carbon monoxide was traced to an exhaust leak on a well water pump and a damaged stove pipe.